Power system control apparatus and power system control method

Abstract

A desired value of reactive power flow between a to-be-controlled power system and an adjoining power system is determined according to measured values of the reactive power flow and an effective power flow and desired voltage values of the to-be-controlled power system and of the adjoining power system. Thereafter, a required value of a reactive power of the to-be-controlled power system is calculated according to the desired value of the reactive power flow, the measured values of the reactive power flow and the effective power flow, and the desired voltage value and a measured voltage value in the to-be-controlled power system. Thereafter, a control apparatus having an electric capacity near to the required value of the reactive power is selected from control apparatus arranged in the to-be-controlled power system to make the selected control apparatus adjust a voltage of the to-be-controlled power system. Therefore, cooperation of the to-be-controlled power system with the adjoining power system can be performed by collecting locally-existing-information, and a voltage fluctuation and/or a reactive power fluctuation in the to-be-controlled power system can be immediately suppressed.

What is claimed is:  
     
       1. A power system control apparatus comprising: 
       power flow measuring means for measuring a reactive power flow and an effective power flow, which respectively flow between a to-be-controlled power system and an adjoining power system adjacent to the to-be-controlled power system, for each adjoining power system;  
       desired value determining means for determining a desired reactive power flow or a desired sum of the reactive power flows according to the reactive power flows and the effective power flows measured by the power flow measuring means, a desired voltage of the to-be-controlled power system, and at least one of a plurality of desired voltages of the adjoining power systems;  
       required value calculating means for calculating a required reactive power of the to-be-controlled power system according to the reactive power flows and the effective power flow measured by the power flow measuring means, the desired reactive power flow or the desired sum of the reactive power flows determined by the desired value determining means, the desired voltage of the to-be-controlled power system, and a measured voltage of the to-be-controlled be-controlled power system; and  
       control means for selecting a control apparatus from a plurality of control apparatuses arranged in the to-be-controlled power system according to the reactive power calculated by the required value calculating means and controlling operation of the control apparatus selected to reduce the required reactive power of the to-be-controlled power system.  
     
     
       2. The power system control apparatus according to claim  1 , wherein the required reactive power calculated by the required value calculating means includes a term obtained by multiplying deviation of the measured voltage of the to-be-controlled power system from the desired voltage of the to-be-controlled power system, by a control constant. 
     
     
       3. The power system control apparatus according to claim  2 , further comprising constant value changing means for changing the control constant or the desired voltage of the to-be-controlled power system when a system configuration of the to-be-controlled power system and the adjoining power system is changed. 
     
     
       4. The power system control apparatus according to claim  2 , further comprising constant value changing means for changing the control constant when the desired voltage of the to-be-controlled power system or the desired voltage of one adjoining power system is changed. 
     
     
       5. A power system control apparatus comprising: 
       power flow measuring means for measuring a reactive power flow and an effective power flow flowing between each of partial power systems of a to-be-controlled power system and an adjoining power system and measuring reactive power flow and effective power flow flowing between one pair of partial power systems adjacent to each other for each pair of partial power systems adjacent to each other;  
       desired value determining means for determining a desired value of the reactive power flowing between one partial power system and the adjoining power system adjacent to the partial power system according to the reactive power flow and the effective power flow, which flow between the partial power system and the adjoining power system, measured by the power flow measuring means, a desired voltage of the partial power system, a desired voltage of the adjoining power system for each partial power system, a desired value of the reactive power flow flowing between one pair of partial power systems adjacent to each other according to the reactive power flow and the effective power flow, which flow between the pair of partial power systems, measured by the power flow measuring means, and two desired voltages of the pair of partial power systems for each pair of partial power systems adjacent to each other;  
       required value calculating means for calculating a required reactive power of each partial power system according to the reactive power flow and the effective power flow which flow between the partial power system and one adjoining power system adjacent to the partial power system, measured by the power flow measuring means, the reactive power flow and the effective power flow which flow between the partial power system and another partial power system adjacent to the partial power system, measured by the power flow measuring means, the desired reactive power flow which flows between the partial power system and the adjoining power system, and the desired reactive power flow which flows between the partial power system and another partial power system adjacent to the partial power system, determined by the desired value determining means, the desired voltage of the partial power system, and a measured voltage of the partial power system; and  
       control means for selecting a control apparatus from a plurality of control apparatuses arranged in one partial power system according to the required reactive power of the partial power system calculated by the required value calculating means for each partial power system and controlling the control apparatus selected, of each partial power system to make the control apparatus selected reduce the required reactive power of the partial power system.  
     
     
       6. The power system control apparatus according to claim  5 , wherein the required reactive power of each partial power system calculated by the required value calculating means includes a term obtained by multiplying deviation of the measured voltage of the partial power system from the desired voltage of the partial power system, by a control constant. 
     
     
       7. The power system control apparatus according to claim  6 , further comprising constant value changing means for changing the control constant or the desired voltage of one partial power system when a system configuration of the partial power systems and the adjoining power systems is changed. 
     
     
       8. The power system control apparatus according to claim  6 , further comprising constant value changing means for changing the control constant when the desired voltage of one partial power system or the desired voltage of one adjoining power system is changed. 
     
     
       9. A power system control apparatus comprising: 
       system predicting means for receiving a load prediction of a to-be-controlled power system and at least one of a plurality of adjoining power system adjacent to the to-be-controlled power system, predicting first electric information of the to-be-controlled power system and second electric information between the to-be-controlled power system and each adjoining power system by calculating a power flow between the to-be-controlled power system and each adjoining power system according to the load prediction;  
       operation predicting means for predicting operation of each of at least one of a plurality of control apparatuses arranged in the to-be-controlled power system according to the first electric information and the second electric information predicted by the system predicting means; and  
       schedule setting means for setting an operation schedule of the control apparatuses according to the operation prediction produced by the operation predicting means to operate the control apparatuses according to the operation schedule.  
     
     
       10. A power system control apparatus according to claim  9 , further comprising: 
       power flow measuring means for measuring a reactive power flow and an effective power flow, which respectively flow between a to-be-controlled power system and each adjoining power system adjacent to the to-be-controlled power system;  
       desired value determining means for determining a desired reactive power flow according to the reactive power flows and the effective power flows measured by the power flow measuring means, a desired voltage of the to-be-controlled power system, and at least one of a plurality of desired voltages of the adjoining power systems;  
       required value calculating means for calculating a required reactive power of the to-be-controlled power system according to the reactive power flows and the effective power flows measured by the power flow measuring means, the desired reactive power flow determined by the desired value determining means, the desired voltage of the to-be-controlled power system, and a measured voltage of the to-be-controlled power system;  
       control means for selecting a control apparatus from the control apparatuses according to the reactive power calculated by the required value calculating means, determining an operation instruction required for the selected control apparatus according to the required reactive power, and providing the operation instruction for the control apparatus selected to reduce the required reactive power of the to-be controlled power system in operation of the control apparatus selected and indicated by the operation instruction; and  
       schedule revising means for revising the operation schedule of the control apparatuses set by the schedule setting means to make a revised operation schedule match the operation of the control apparatus selected by the control means when the control apparatus selected by the control means or the operation of the control apparatus selected by the control means does not match the operation schedule of the control apparatuses, the control apparatuses being operated according to the revised operation schedule.  
     
     
       11. A power system control apparatus comprising: 
       electric information predicting means for calculating a predicted value of first electric information corresponding to a to-be-controlled power system from a measured value of the first electric information of the to-be-controlled power system;  
       communicating means for receiving a predicted value of second electric information and a measured value of the second electric information from each of at least one of a plurality of adjoining power systems adjacent to the to-be-controlled power system;  
       operation predicting means for predicting operation of each of a plurality of first control apparatuses arranged in the to-be-controlled power system from the predicted value of the first electric information and the measured value of the first electric information, produced by the electric information predicting means, and predicting operation of each of a plurality of second control apparatuses arranged in one adjoining power system from the predicted value of the second electric information and the measured value of the second electric information received by the communicating means from the adjoining power system for each adjoining power system;  
       control means for selecting one of the first control apparatus from the first control apparatuses arranged in the to-be-controlled power system according to the operation prediction or the first control apparatuses and the operation prediction for the second control apparatus produced by the operation predicting means and controlling the control apparatus selected to adjust the first electric information of the to-be-controlled power system to the predicted value produced by the electric information predicting means.  
     
     
       12. A power system control method comprising: 
       measuring a reactive power flow and an effective power flow, which respectively flow between a to-be-controlled power system and an adjoining power system adjacent to the to-be-controlled power system;  
       determining a desired reactive power flow according to the reactive power flow measured and the effective power flow measured, a desired voltage of the to-be-controlled power system, and a desired voltage of the adjoining power systems;  
       calculating a required value of reactive power of the to-be-controlled power system according to the reactive power flow measured, the effective power flow measured, the desired reactive power flow, the desired voltage of the to-be-controlled power system, and a measured voltage of the to-be-controlled power system;  
       selecting a control apparatus from a plurality of control apparatuses arranged in the to-be-controlled power system according to the required reactive power; and  
       controlling operation of the control apparatus selected to reduce the required reactive power of the to-be-controlled power system.  
     
     
       13. A power system control method comprising: 
       measuring a reactive power flow and an effective power flow flowing between each of partial power systems of a to-be-controlled power system and an adjoining power system adjacent to the partial power system;  
       measuring a reactive power flow and an effective power flow flowing between one pair of partial power systems adjacent to each other for each pair of partial power systems adjacent to each other;  
       determining a desired reactive power flow flowing between one partial power system and the adjoining power system adjacent to the partial power system according to the reactive power flow measured and the effective power flow measured flowing between the partial power system and the adjoining power system, a desired voltage of the partial power systems, and a desired voltage of the adjoining power system for each partial power system;  
       determining a desired reactive power flow flowing between one pair of partial power systems adjacent to each other according to the reactive power flow measured and the effective power flow measured as flowing between the pair of partial power systems, and two desired voltages of the pair of partial power systems for each pair of partial power systems adjacent to each other;  
       calculating a required reactive power of each partial power system according to the reactive power flow measured and the effective power flow measured as flowing between the partial power system and one adjoining power system, the reactive power flow measured and the effective power measured as flow flowing between the partial power system and another partial power system adjacent to the partial power system, the desired reactive power flow flowing between the partial power system and the adjoining power system, the desired reactive power flow flowing between the partial power system and another partial power system adjacent to the partial power system, the desired voltage of the partial power system, and a measured voltage of the partial power system;  
       selecting a control apparatus from a plurality of control apparatuses arranged in one partial power system according to the required reactive power of the partial power system for each partial power system; and  
       controlling operation of the control apparatus of each partial power system selected to reduce the required reactive power of the partial power system.  
     
     
       14. A power system control method comprising: 
       receiving a load prediction of a to-be-controlled power system and of at least one of a plurality of adjoining power systems adjacent to the to-be-controlled power system;  
       predicting first electric information of the to-be-controlled power system by calculating a power flow between the to-be-controlled power system and each adjoining power system according to the load prediction;  
       predicting second electric information between the to-be-controlled power system and each adjoining power system according to the load prediction;  
       predicting operation of each of at least one of a plurality of control apparatuses arranged in the to-be-controlled power system according to the first electric information and the second electric information; and  
       setting an operation schedule of the control apparatuses according to the operation prediction to operate the control apparatuses according to the operation schedule.  
     
     
       15. A power system control method comprising: 
       calculating a predicted value of first electric information corresponding to a to-be-controlled power system from a measured value of the first electric information of the to-be-controlled power system;  
       receiving a predicted value of second electric information and a measured value of the second electric information from each of at least one of a plurality of adjoining power systems adjacent to the to-be-controlled power system;  
       predicting an operation of each of a plurality of first control apparatuses arranged in the to-be-controlled power system from the predicted value of the first electric information and the measured value of the first electric information;  
       predicting operation of each of a plurality of second control apparatuses arranged in one adjoining power system from the predicted value of the second electric information and the measured value of the second electric information received from the adjoining power system for each adjoining power system;  
       selecting a particular first control apparatus from the first control apparatuses arranged in the to-be-controlled power system according to the operation prediction for the first control apparatuses and the operation prediction for the second control apparatuses; and  
       controlling the control apparatus selected to adjust the first electric information of the to-be-controlled power system to the predicted value.